Telomers of vinyl alkanoates and alkanols and preparation thereof

ABSTRACT

TELOMERS OF VINYL ESTERS, SUCH AS VINYL ACETATE, WHEREIN THE TELOGEN IS AN ALKYL ALCOHOL CONTAINING UP TO 8 CARBON ATOMS, AND A METHOD OF PREPARING SAID TELOMERS BY REACTING THE VINYL ESTER WITH THE TELOGEN AT A TEMPERATURE OF 90* TO 250*C. AND A PRESSURE OF 50 TO 7500 P.S.I. IN THE PRESENCE OF A FREE-RADICAL-FROMING CATALYST OR INITIATOR EFFECTIVE FOR THE POLYMERIZATION OF VINYL ACETATE, THE VINYL   ESTER AND THE TELOGEN HAVING A RESIDENCE TIME IN THE REACTION OF 0.5 TO 60 MINUTES, PREFERABLY 1 TO 10 MINUTES.

April 16, 1974 K OFF ETAL 3,804,886

TELOMERS OF VINYL ALKANOATES AND ALKANOLS AND PREPARATION THEREOFOriginal Filed July 31. 1964 CONDENSER S TR/PPER mu wru REACTOR HEA Tenmm mm United States Patent TELOMERS OF VINYL ALKANOATES AND ALKANOLS ANDPREPARATION THEREOF Joseph K. Holfman, Morristown, and James P. Russell,

.Scotch Plains, N.J., assignors to Air Products and Chemicals, Inc.,Allentown, Pa.

Continuation of abandoned application Ser. No. 386,593, July 31, 1964.This application Dec. 30, 1969, Ser. No. 888,129

Int. Cl. C07c 67/00, 69/16, 69/22 US. Cl. 260-488 J Claims ABSTRACT OFTHE DISCLOSURE Telomers of vinyl esters, such as vinyl acetate, whereinthe telogen is an alkyl alcohol containing up to 8 carbon atoms, and amethod of preparing said telomers by reacting the vinyl ester with thetelogen at a temperature of 90 to 250 C. and at a pressure of 50 to 7500p.s.i. in the presence of a free-radical-forming catalyst or initiatoreffective for the polymerization of vinyl acetate, the vinyl ester andthe telogen having a residence time in thereaction of 0.5 to 60 minutes,preferably 1 to 10 minutes.

During the reaction, the telogen is split into radicals which attach tothe ends of the telomerizing taxogen and, in some cases, add to thedouble bond of the taxogen and form chains 'with terminal groupscomposed of the radicals formed from the telogen. Telomerizationis.discussed, for example, in Hanford et al., US. Pat. 2,418,832 of Apr.15, 1947. Thus, if the telogen is-repre sented as YZ, telomers can berepresented as Y(A),,Z, wherein (A) is a divalent radical formed bycondensation of the taxogen, n being any integer greater than one, and Yand Z being fragments of the telogen attached tothe terminal. portionsofthe radical (A) Telomers are different from copolymers and/orinterpolymers. Copylymers and/or interpolymers contain a number of eachof two or more different monomer units in the main polymer chain,whereas the fragments of another molecule (the telogen) in telomersappear as. units at the terminals of the main telomer chain.

Telomerization also differs from simple free-radical ad-" dition tothedouble bond'of an olefinic monomer in that more than one molecule of theolefinic monomer appears in the product. The telomerization reactionprocecds in: the presence of a free radical initiator which removes anactive hydrogen-from the telogen. The re-' sulting radical initatesthe'telomerization by adding to the double bond of the taxogen. I

Organic hydrocarbons containing an olefinie' double bond, such asethylene, propylene, hexeue, octene, and

styrene are normally employed as taxogens, and various compounds havebeen employed'as telogens. It will be understood that within theframework of the telomerization process as above defined, it is possibletoproduce products having very different structures and characteristics,depending upon the taxogen and telogen used and upon the process oftelomerization employed. Telomerization and numerous telomers which haveheretofore been produced are described in publication No. PBl31- 930,publishedbythe U.S. Department of Commerce, Ofiice of TechnicalServices, and entitled, Teiomerization-A Review of the Literature, by R.B. Fox and D. E. Field.

While some telomers have beenformed from vinyl esters, suuh as vinylacetate, these monomers have been used only to a very limited extent intelomerization reactions and the resuiting products have not hadgenerally satisfactory properties. The telomerization reaction has,accordingly, been used for the most part with other monomeric compounds,especially ethylene and related unsaturated hydrocarbons.

It is an object of this invention to provide novel telomers from vinylesters such as vinyl acetate.

It is another object of the invention to provide telomers from vinylesters which exhibit desirable characteristics such as heat stability,and freedom from color.

It is a further object of the invention to provide an improved processfor producing telomers of the character indicated.

In accordance with the invention, a vinyl ester of the formulaRC'OOCH=CH2' wherein R is an alkyl group, especially a lower alkylgroup, e:g. having up to 6 carbon atoms, is telomerized by heating it atan elevated temperature of to 250 C. at a pressure of 50 to 7,500p.s.i.g., in the presence of a radical-forming catalyst or initiator andin the presence of a telogen. In a particularly advantageous process inaccordance with this invention, the telomerization is carried out underthe foregoing conditions of temperature and pressure by continuouslypassing the vinyl ester, telogen, and catalyst mixture through atelomerization zone wherein the telomerization mixture has a residencetime of 0.5 min. to '60 min., preferably 1 min. to 10 min. The pressurein the telomerization zone is maintained at a value the foregoing rangesuch that the vinyl ester monomer, and the telogen, are continuously inthe liquid phase. Advantageously, although not necessarily, the reactionmixture is preheated lbefore introduction into the reaction zone tobring it to within about 20 to 50 C. of the intended reactiontemperature and the residence time in the preheating zone is justsufiicient to accomplish the desired preheating.

Particularly good results are achieved, and a particularly desirableproduct is obtained, when the telogen is an aliphatic alcohol containingfrom 1 to 3 carbon atoms, especially isopropanol. Such telomers can berepresented by the formula wherein n is an integer having a value of 1to 150, R is a methyl or ethyl radical, and R is hydrogen or a methylTypical c o-taxogens which ether and n-butyl vinyl ether, propylene,alpha-olefins such as l-butene, lower alkyl maleates, such as dibutylmaleate, -acrylonitrile, vinyl benzoate, vinyl cyclohexene,cyclododecene, vinylidene chloride, acetylene, and the like. In formingco-telomers the ratios between the two taxogens can vary, but the vinylester represents at least 25 mol percent, preferably at least 50 molpercent of the combined taxogens.

' The ratio between the telogen and the taxogen or taxogens can alsovary, but the telogen is always present in an amount of at least byweight of the taxogen or taxogens, and preferably at least 30% byweight, and a practical upper limit on the amount of telogen is 90% byweight of the taxogens. I

'Telomers can be produced in accordance with this invention which havelow viscosity and high solvating and plasticizing properties so thatthey form more fluid bodies at lower temperatures than is possible withthe homopolymer or copolymers formed from the taxogen or taxogens alonein the absence of the telogen. As a result, the telomers of thisinvention are particularly suitable for use in hot-melt-coatings oradhesives for application to paper, leather, and cloth because they donot have to be heated, in order to place them in a sufficiently fluidcondition for coating, to temperatures which tend to discolor theresins. The telomers and co-telomers are also useful as plasticizers forelastomers and resins, such as polyvinyl chloride. The preferred vinylacetateisopropanol telomer of this invention is a particularly clear,glass-like product and, by varying the ratio of isopropanol to vinylacetate, it is possible to provide telomers having a wide variety ofmolecular weights so that they can be easily tailored to variousspecific hot-meltcoating and plasticizing uses.

As catalysts which, are useful in carrying out the reaction of thisinvention, there can be used any freepolymerization of vinyl acetate.Particularly useful catalysts include compounds having directly linkedoxygen atoms, e.g. peroxygen compounds such as diacyl peroxides, e.g.benzoyl peroxide, propionyl peroxide, and lau'royl peroxide, dialkyl anddialkylaryl peroxides such as ditertiary-butyl peroxide and di-cumylperoxide, and otherperoxide s such as ascaridole, diethylperdicarbonate, hydrogen peroxide, and tertiary butyl hydro-perm;- 'ide.1Particularly preferred is di-teritary-butyl peroxide. jU.V. light canbe used in conjunction with any' compound, which photolizes 'under theinfluence of UN. light to produce radicals;'e.g. acetone. Also suitableas catalysts are azo-nitrile catalysts, such as disclosed, in Hunt 115.Pat. No. 2,471,959, e.g. azo-bis-iso-butyronitrile, which iscommerciallyreferred to in the art as AZN. I The amount of catalystemployed can vary, but-itis most suitably used in the amount of 0.01to5.0% by weight, calculated on the basis of the vinyl ester, preferably0.1 to 1.0% by weight.

While the process of this invention can be carried out in any convenientapparatus, there are illustrated in the accompanying drawingparticularly suitably apparatus systems. In the drawing,

FIG. 1 is a diagrammatic view of a continuous telomer preparation andrecovery train showing, in particular, apparatus for carrying out thecontinuous 'telomerization reaction;

FIG. 2 is a diagrammatic view of the modified form of'continuoustelomerization vesselwhich can be substituted for the telomerizationvessel in the train of FIG.

and I, v v

FIG. 3 is a diagrammatic view of a batch telomerization vessel forreplacing the continuous telomer ization vessel in the train of FIG. 1when batch operation is desired.

can be used with vinyl esters include ,crotonic acid, vinyl ethers, suchas 2-propyl vinyl 7 Referring to the drawing and particularly to FIG. 1,

the system illustrated includes a telogen supply vessel 10 provided withan agitator 12 and inlets 14 and 16 for the telogen and the catalyst,which are suitably premixed in the vessel 10. The contents of vessel 10are discharged through an outlet conduit 18. The taxogen, e.g. vinylacetate, is supplied from a supply vessel 20 having an inlet 22 and anoutlet conduit 24. Outlet conduits 18 and 24 are provided with pumps 26and 28, respectively, which discharge into a common conduit 30 whereinthe telogen-catalyst mixture and the taxogen are mixed in the'proportions determined by the pumps 26 and 28. Conduit 30 leads to thecoil 34 of a continuous coil preheater 32 which is adapted to contain aheat transfer medium, e.g. oil, for maintaining the coil 34 at thedesired preheating temperature. Inlet 36 and outlet 38 are provided forcirculation of the heat transfer medium through the vessel 32. Theoutlet end of coil 34 communicates with a conduit 40 containing a pump42 which leads to the inlet of the coil 46 of the continuous coilreactor or telomerization unit 44 which, like the preheater 32, isadapted to contain a heat transfer medium, e.g. oil, to maintain thecoil 46 at the desired reaction temperature. An inlet 48 and an outlet50 are provided for circulation of the heat transfer medium. The outletend of. the coil 46 is connected to a conduit 52, containing a valve 53,which leads to a distillation or stripping column 54 in which thevolatile components of the reaction mixture, e.g. unreacted telogenand/or taxogen are separated from the telomer, the latter beingWithdrawn through a line 56 and condensed in a condenser 60. Thecondensate from the condenser 60 is separated and recycled to thesystem.

[Instead of a continuous coil reactor as shown at 44 in FIG. 1, goodresults can also be obtained with a continuous reactor of the agitatortype Whereinthe reactants are continuously introduced into' acontinuously-stirred body of the reaction mixture and correspondingamounts of the reaction mixture are continuously withdrawn so that thevolume of the body of the reaction mixture remains substantiallyconstant. Such a reaction vessel isshown diagrammatically in FIG. 2,wherein parts corresponding to those shownin FIG. 1 are given the samereference numeral to which'a has been added. As seen in FIG. 2; areactor 44a has an inlet 40a at its bottom and an outlet 52a at its top,provided with a valve 53a. The outlet 52a is suitably arranged as shownso thatthe vessel 44b is always filled with liquid. The vessel,44b issuitably provided with an agitator 70 and is heated in any convenientmanner (not shown) as by a jacket, strip heaters, or the like, as wellknown in the art 'In some cases it maybe desirable to carry out telomerization in accordance with this invention in' a batchwise manner. Inthat event, a batch reaction vessel is suitably substituted for thereactor 44 in FIG. 1. FIG. 3 illustrates diagrammatically a typicalbathf reaction vessel, and in FIG. 3 parts corresponding to those shownin FIG. 1 have b'een giventhesame reference numeral to which b has beenadded. Thus, the batch reactor in FIG. 3 comprises a-ves'sel 44b'havingan inlet 40b, and an outlet'52b containing a valve 53b, and is providedwith astirrer 70; Like thereactor 44a shown in FIG. 2, reactor 44 isadvantageously provided with heating means (not shown). The reactors ofFIGS. 2 and 3 are conveniently in the form of autoclaves. The objectsandfeatures of the invention will be further apparent from the followingspecific examples of practical application, it being understoodthat-these examples are given solely by way of illustration and notlimitation.'

r EXAMPLE 1 Using a continuous coil reactor system such as shown in FIG.1 wherein the preheater coil 34 is made of A in.

copper tubing having a volume of 100 ml., and the reactor coil 46 is a aA in. copper coil having a volume of 140 .mL, a feed stock consisting of2000 'ml. of vinyl acetate and 1000 ml. of Z-propanol containing 5 ml.of di-tertbutyl peroxide, illustrative of a vinyl acetate-propanol ratioof 2:1, is continuously passed through the system. The preheater 32 ismaintained at about 135 C. and the reactor temperature is maintained atabout 155 C. The pumps 26, 28 and 42 are operated to provide arateofflow of the telomerization mixture through the system of 14 ml./min.,and the valve 53 is controlled to maintaina pressure of 225-250 p.s.i.g.The reaction is continued for about 4 hours. The product is stripped instripper 54, which is maintained at atemperature of about 175 C., toremove the non-reacted liquids, and the product telomer is collectedfrom the bottom of the stripper in a suitable receiver. At the rate offlow indicated, the residence time of the telomerization mixture isabout 7 minutes in the preheater 32 and about minutes in the reactor 44.A typical vinyl acetate-propanol telomer' produced in the system andunder the conditions described had a molecular weight of about 3000 andwas produced with a conversion of about 90%.

The following tabulation shows the results of corresponding operationsin which the reactor temperature, the ratio of vinyl acetate to2-propanol, or the content of catalyst has been varied:

Catalyst Reactor Percent Telomer (percent temp., convermoi. Ratioweight) C. slon weight In another series of reactions involving thepreparation of a vinyl acetate-isopropanol telomer with the taxogen andthe telogen in a 2:1 ratio, using di-t-butyl peroxide as catalyst, theresults of varying the residence time, the temperature, and the catalystwere observed, as follows:

Catalyst Prod Temp cone. mol Residence time, min. percent EXAMPLE 2 Thecontinuous telomerization reactionof' this invenpreparation of vinylacetate-Z-propanol telomers in operations extending for many hours andwith substantial vol-' umes of reactants, the reaction zone being 100ft. of tubing. In all cases the catalyst content was 0.25 volumepercent, based on the 2-propanol, the pressure was about 265 p.s.i.g.,and conversions exceeded Flow Reactor 6 EXAMPLE 3 Although particularlyeffective results are obtained, in accordance with the invention, byusing the continuous coil reactor employed in the foregoing examples,the continuous process of the invention can be modified by using areactor of the continuous agitator type, as shown in FIG. 2, in a systemas illustrated in FIG. 1.

Thus, using a continuous reactor in the form of a 200 cc. stirredautoclave heated to about 150 C., a feed stock consisting of 2000 ml. ofvinyl acetate and 2000 ml. of 2-propanol containing 5.0 ml. ofdi-tert-butyl peroxide is continuously passed through the system. Inthis system it is generally not necessary to employ pre-heating, and thereactants can be fed directly to the reactor at ambient temperature.Thus, when the continuous overflow reactor 44a, sown in FIG. 2, isemployed in the system of FIG. 1, the pre-heater 32 can, if desired, beomitted and the line 30 joined directly to the line 40. In the presentexample, no pre-heater is used and the feed stock is fed to theautoclave at an ambient temperature of about 25 C. The pressure on thesystem is about 200 p.s.i.g. and the residence time in the reactor isabout 10 minutes. The reaction is continued for about 4 hours and theproduct is stripped in a stripping zone maintained at a temperature ofabout 175 C., to remove the non-reacted liquid and theproduct telomer iscollected from the bottom of the stripper in a suitable receiver. Atypical vinyl acetate-isopropanol telomer produced in the system, andunder the conditions described, had a molecular weight of about 790 andwas produced with a conversion of about 92.5%. When the foregoingoperation is repeated with variations in ratios,'residence times, andtimes of reaction, the following results are obtained:

Residence Telomer Vinyl aeetateztelogen ratio time, mins. Mol. wt.

EXAMPLE 4 Flow rate, Reactor Telome. gals. per temp., molrIsopropanolzvinyl acetate ratio min. 0. wt.

EXAMPLE 5 This example illustrates the preparation of a vinylacetate-isopropanol telomer in a batch process, i.e. using atelomerization kettle such as illustrated diagrammatically in FIG. 3.The reactor was a stirred 1 gal. autoclave fitted with anelectrically-heated jacket and an internal cooling coil with provisionsfor air or water cooling. The pre-mixed reagents consisting of 500 ml.vinyl acetate (at 5 C.) 2000 ml. 2-propanol (at 22 C.) and 10 ml.di-t-butyl peroxide (at 5 C.) were charged into the autoclave and theautoclave was flushed twice with 100 p.s.i.g. of nitrogen. The heat wasstarted at 260 volts and kept on until the jacket temperature reached C.The heat was cut back to 160 volts and the temperature controllerswitched to indicate the inside temperature. When the inside temperaturereached air cooling was started. The temperature rose rapidly to Watercooling was then started and time started. The temperature wascontrolled at 148-150 by use of alternate cooling and heating for 60min. The heat was then discontinued and water cooling started. When theinside temperature reached 35 C. the reactor was vented and the chargeremoved.

The charge was placed in a 1 in. x 14 in. Vigreaux still and stripped ofvolatiles to a pot temperature of 150 C. The pot was allowed to cool to110 C. and a vacuum was applied. The product was then vacuum stripped toa pot temperature of 150 C./0.4 mm. The products consisted of 485 g. oftelomer of 800 mol. wt. and containing about 94% vinyl acetate, and 20g. high boiling, volatile by-products, B.P. 62-65 0.4 mm. The distillatetaken oflf at atmospheric pressure was topped on a 60 plate still giving12 g. products boiling under 74 C. consisting mainly of vinyl acetate.

The foregoing operations were repeated with varying ratios of telogen tovinyl acetate, with the following results:

Amt. vinyl Telomer acetate in Telogemvinyl acetate ratio mol. wt. prod.

EXAMPLE 6 Other telomers and co-telomers of vinyl acetate are similarlyproduced by the procedures described and illustrated above, withparticularly efiective results being obtained in the continuous systems.The following table gives pertinent data with respect to a series ofruns carried out batchwise with vinyl acetate and telogens other thanisopropanol, with the operating data and the characteristics of theproduct being indicated:

The telomers described above are viscous to hard and brittle productswhich are non-volatile at temperatures up to 200 C. at a pressure of 0.1mm. of Hg. Normally, the only volatile component of the reaction mixtureconsists of unreacted telogen and taxogen. However, in Example 5 thehigh boiling volatile by-product described, which was also obtained inthe case of the last telomer listed in the table, is a 1:1 vinylacetate-isopropanol telomer. Similarly, in the telomers of methanol andethanol listed above, there were obtained small amounts of 1:1 telomers,the vinyl acetate-methanol telomer boiling at 55-60 C. at 0.1 mm. of Hg,and the vinyl acetate-ethanol telomer boiling at 60-62 C. at 0.75 mm. ofHg.

As previously indicated, this invention is also concerned with thepreparation of co-telomers, i.e. telomers which are formed from atelogen, a lower alkyl vinyl ester, such as vinyl acetate, and anothertaxogen, viz. another unsaturated polymerizable monomer.

The following examples illustrate the preparation of a number of vinylacetate co-telomers, generally with isopropanol as a telogen but, insome cases, using other telogens. The preparation of these co-telomerswas effected by means of the processes described above.

EXAMPLE 7 In this example, propylene was used as the co-taxogen, withisopropanol as the telogen. The following table gives the results ofbatch operation with the propylene being supplied to the reactor under apressure of 5000 p.s.i.g. The reactions were carried out at 150 C.

Pro- Vinyl pyl- Peracetate Prod. ene oxide Time Prod. percent moi. (ml.)(g (hrs.) (g.) in prod. wt.

EXAMPLE 8 In this example the co-taxogen is an alpha-olefin containingfrom 4 to 10 carbon atoms. The operations described in the followingtable were carried out at 150 C. with a 1% catalyst (di-t-butylperoxide) concentration and a 1:1 volume ratio of taxogenszisopropanol,with a 60 minute reaction time.

The reactor used for these operations was a 1-liter stirred autoclavewhich was electrically heated and fitted with an internal cooling coil,stirrer, and thermocouple well. A stainless steel liner was used tocontain the reaction mixture. The reactor was fitted with a pressuregauge and provisions for flushing with dry nitrogen.

The charge, which consisted of vinyl acetate, telogen, catalyst, andco-taxogen was prepared in advance. Volumes of reagents were adjusted sothat the total volume charged was between 400 and 500 cc. The charge wasplaced in the autoclave and the reactor flushed twice with 500 p.s.i.g.N A residual pressure of 20 p.s.i.g. N was left on the reactor andheating and stirring started. When the temperature reached the heat wascut back to 30 volts. When the temperature reached the maximum pressurewas recorded (120-180 p.s.i.g.) and time of reaction was started. After60 min. at 150 (cooling with air or water occasionally needed) thereaction was rapidly cooled with water, and the charge was removed fromthe autoclave when the temperature reached 40 C. The product solutionswere transferred to a 500 ml. distilling flask and weighed. The productsolutions were vacuum stripped on a 14 in. x 1 in. Vigreaux still to apot temperature of 170- C./0.1 mm. Hg.

Mol ratio vinyl Prod. Percent acetate mol. olefin in Co-taxogenco-taxogen wt. prod.

l-decene 2. 4 1, 250 35 l-octene 2. 0 1, 350 35 1-hexene......-- 1. 6 1,300 30 l-butene 1. 4 1, 200 21 In the following table are shown theresults of operatrons carried out as described above, except thatgreater oleln to vinyl acetate ratios were employed:

Prod. Percent Cotaxogen wt. prod.

1-decene-- 1,560 53.4

l-octene 1,500 54 EXAMPLE 9 Co-taxm Taxogen- Prod. Co-taxogen gen (vol.to ratio mol. in prod. Co-taxogen Telogen percent) telogen wt.,(percent) Vinyl cyclo- 2-propanol.. 50 1 670 A hexene. Cyclododec-..-..do 50 1 1,160 17 ene. Iso-butyl Ethyl ace- 50 1 1, 240 '34 vinylether. tate. Vinylidene .-.do 20 1.25

chloride. Acrylonitrile. Toluene 20 1.25

1 Two products formed in this reaction:

1. a toluene-soluble 63 g., (mol. wt.'2,900) with 3.4% acrylonitrile'.2. a toluene-insoluble 105 g. (mol. wt. 5,900) with 28.5%.acrylonitrile,

which is soluble in acetone and acetonitlile.

EXAMPLE This example illustrates the use of crotonic acid as aco-taxogen with vinyl acetate, employing various telogens, includingisopropanol. The data relating. to .the preparation of the severalco-telomers, carried out at 150 C. for 1 hour, are set forth in thefollowing. table:v

. 10 several co-telomers, carried out at 150 C. and with a reaction timeof one hour, are set forth in the following table:

Ratio Prod. Raticco-taxogento telogento Percent mol. Charactervinylacetate taxogens catalyst wt. ofprod.

3:1 1 987 Solidglass. 8:1 1 635 Very viscous. 4:1 1 907 Brittle. 7:1 1650 Very viscous. 4.5:1 1 900 Almost brittle.

The foregoing telomers contained about 30 to 50% of vinyl *benzoate.

EXAMPLE 13 v In this example acetylene was used as a co-taxogen withvinyl acetate, employing isopropanol and toluene as the telogens. Thedata relating to the preparation of the cotelomers, at 150 C. with areaction time of one hour, are set forth in the following table:

Crotonlc acid Ratio Prod. Crotonic Acetyin vinyl acetelogen to Percentmol. acid in Vinyl lene, Ratio Percent tate, percent Telcgen taxogenscatalyst wtprod. acep.s.i.g. telegen to Percent Prod. vinyl tate, atvinyl catamol. acetate 2.5 Toluene 1:1 3 2,400 2.7 Telogen g. C. acetatelyst wt. in prod. 5.--- ..do..-.- 1:1 3 3,350 6. 1 25 5- --d0.-..-----1:1 1 3, 000 5. 7 Toluene 93 80 3: 1 1 766 79 5 --d0 1:1 0.5 3,400 6.9Do 93 50 3:1 1 998 88 5.. Ethyl acetate. 1:1 0. 5 5, 300 6. 0 Do 93 253:1 1 1, 070 86 5.. .-do 1:1 3 4, 700 5.4 Do 93 25 4:1 1 836 82 5Isopropanol-.- 1:1 1 2, 400 7.4 Isopropanol... 93 80 3:1 1 696 80 T f gg pr d cts were produced m a batch 0p- As previously mentioned,telomers, broadly, can be eration. The reaction was also carried out ina continuous system such as shown in FIG. 1, at 158 C., with a catalystconcentration of 1% and a residence time of 10 min., using 5 g. ofcrotonic acid'per 100 ml. of vinyl acetate and a telogen to taxogenratio of 1:1. The following results were obtained:

Prod. Crotonic mol. acid in Telogen wt. prod.-

2-propanol 1,900 6.1 Toluene 2,900 7.6 Ethyl acetate.. 5,200 6.4

The products were all brittle solids which were soluble in cold 2%aqueous NaOH. The yields were over 98%.

EXAMPLE 11 This example illustrates the useof vinyl ethers as'cotaxogenswith vinyl acetate, employing various telogens. The data relating to thepreparation of the several cotelomers, carried out at 150 C. for 1 hour,using 1% catalyst and a taxogenztelogen ratio of 1:1, are set forth inthe following table:

The foregoing products were produced in a batch operation. This reactionwas also carried out in a continuous system, using 20% n-butyl vinylether, with 1% catalyst, and a taxogenztelogen ratio of 1:1. Thetemperature was 155 C. and the residence time 10 min. The product,produced in 80% conversion, had a molecular weight of 3400 and a vinylether content of 8 1 EXAMPLE 12 This example shows the use of vinylbenzoate as a co-taxogen with vinyl acetate, employing isopropanol asthe telogen. The data relating to the preparation of the represented bythe formula Y(A) Z wherein Y and Z are, as specified above, thefragments of the telogenattached to the terminal portions of the radical(A),,. It will be apparent that co-telomers can be represented by theformula where (B) is the divalent radical formed by condensation of theco-taxogen. More specifically, the vinyl ester co-telomers of thisinvention can be represented by the formula wherein R is an alkyl group,especially a lower alkyl group, and wherein Y and Z are the fragments ofthe telogen. Similarly, the co-telomers of the invention can berepresented by the formula wherein R is H or the characteristic radicalattached to the group of the co-taxogen linked with the vinyl groups ofthe vinyl ester taxogen. As previously mentioned, n has a value of 1 to150, and in the case of co-telomers the value of m would generally be 1to 150.

One of the features of the processes described above is that not onlycan telomers be produced in which the integer n in the formulae listedcan have a relatively high value, e.g. up to 150, but it is alsopossible to prepare telomers in which n, in these formulate, has a valueof 1. These 1:1 telomers have been referred to above in the case ofvinyl acetate-methanol, vinyl acetate-ethanol, and vinylacetate-isopropanoi. However, in the previous instances the 1:1 telomerswere produced only in small amounts along with higher telomers. Inaccordance with this invention the 1:1 telomers can be prepared as amajor product, by using appropriate conditions. These conditionscomprise a high alcohol to vinyl acetate ratio, i.e. at least 8:1, and ahigh content of catalyst, i.e. at least about 2% based on the vinylester in the case of batch operations, and an alcohol to vinyl acetateratio of at least about 2:1 and a high catalyst content, i.e. at leastabout 6% in the case of continuous operation. Particularly useful is thevinyl acetate-isopropanol telomer which has the formula This and theother 1:1 telomers are useful as solvents in paints, lacquers, and othercoating compositions containing polymers or telomers, and they areparticularly effective as solvents for the non-volatile telomers of thisinvention. The following examples illustrate the preparation of theabove described novel 1:1 vinyl acetate-isopropanol telomer.

EXAMPLE 14 In a stirred autoclave was placed a charge consisting of 3000m1. of 2-propanol, 300 ml. of vinyl acetate and 6 g. of di-t-butylperoxide. The autoclave was purged with nitrogen, sealed, and heated to150 C. for 60 min. The autoclave was then rapidly cooled to 40 C. anddischarged, and the product solution was distilled at 760 mm. to a pottemperature of 150 C. The pressure was then reduced to 25 mm. and thefraction boiling at 112 C. at 25 mm. Hg was collected. The yield was 45ml. of 4-acetoxy-2-methyl-2-butanol, N =1.4294.

EXAMPLE 15 To demonstrate that it is possible to make the product ofExample 14 in a continuous process, the overflow reactor system of FIG.2 was run at 150 C. with a 10 min. residence time on a charge consistingof 5000 ml. of 2-propanol, 2500 ml. of vinyl acetate, and 167 g.di-tbutyl peroxide. Separation of the products by flash distillationfollowed by vacuum distilation gave 250 ml. of4-acetoxy-Z-methyl-2-butanol.

It will be apparent to those skiled in the art that various changes andmodifications may be made in the embodiments described above withoutdeparting from the invention as defined in the appended claims. It isintended, therefore, that all matter contained in the foregoingdescription and in the drawings shall be interpreted as illustrativeonly and not as limitative of the invention.

What is claimed is:

1. A process for making telomers of a vinyl ester of a lower alkanoicacid which consists essentially of reacting a taxogen consistingessentially of said vinyl ester in the presence of afree-radical-forming catalyst or initiator with a telogen which is analkanol containing up to 8 carbon atoms at a temperature of 90 to 250 C.and at a pressure of 50 to 7,500 p.s.i., the telogen being present inthe amount of 10 to 90% by weight of the vinyl ester, said reactionbeing carried out in a telomerization zone wherein said vinyl ester andsaid telogen have a residence time of 0.5 to minutes.

2. A process a defined in claim 1, wherein said reaction is carried outby continuously introducing the vinyl ester, the catalyst and thetelogen into said telomerization zone.

3. A proces as defined in claim 1, wherein the residence time is 0.5 to10 minutes.

4. A process as defined in claim 2, wherein the residence time is 0.5 to10 minutes. I

5. A process as defined in claim 1, wherein the telomer produced has amolecular weight of 450 to 10,500.

6. A process as defined in claim 2, wherein the telomer produced has amolecular weight of 450 to 10,500.

7. A telomer of a taxogen consisting essentially of vinyl acetate with atelogen which is an alkanol containing up to 8 carbon atoms, saidtelomer having a molecular weight of 450 to 10,500, and wherein thetelogen is present in the amount of 10-90% by weight of the vinylacetate.

8. A process as defined in claim 1, wherein said alkanol is isopropanol.

9. A telomer as defined in claim 7, wherein said alkanol is isopropanol.

References Cited UNITED STATES PATENTS 2,402,137 6/1946 Hanford et a1.260-488 2,423,497 7/ 1947 Harmon 260597 2,476,053 7/1947 Lippincott260491 2,594,560 4/1952 Howard, Jr. 260597 OTHER REFERENCES Yamshita, C.A., 53: 16944-945 (1959). Gault et al., C. A., 51: 6506g (1957). Zeileet al., C. A., 44: 2483i (1950).

LEWIS GO'ITS, Primary Examiner V. GARNER, Assistant Examiner US. Cl.X.R.

117-142, 154; 204-158 HE; 2603l.4 R, 31.6, 465 D, 465.4, 476 R, 484 A,488 CD, 488 R, 491

mu I .x A lkJJ-J m rvt a mt n Eli-ii ii .iufai. it .L Patent No.3,804,886 D t d 16 A ril 1976 In enwfls) Joseph K. Hoffman & James P.Russell It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 5, "Teiomeriza-" should be-Telomeriza- 6 Column 2, line9, "suuh" should be--- such'-' Column 2, line 11, "resuiting" shouldbe-resulting-'- Column 2, line 65, "ethy" should beethyl- 1 Column 3,'lines 38-39, after "any free" and before "polymerization"insert-radicalforming catalyst or initiator effective for the- Column 6line 47, "Tel'ome" should be--Telomer- Column 6, line 48, "molr" shouldbe--mol.-

Column 9, line 57, "Teiogen" should be-Telogen- Column 10, line 69,"formulate" should be--formulae- G i Column 10, line 72, "isopropanoi"should be-isopropanol Column 11, line 43, "distilation" shouldbe-distillation- Q In the Claims:

Claim 2 Column 12, line 13, "a" should be--asfiigncd and Sealed thistwentieth Day of April1976 [SEAL] Arrest.-

RUTH C. M X SON C. MARSHALL DANN Arresmzg Officer (ommissium'r qflarenlsand Trademarks

